Leo's advice was very good.
Personally, I feel that plants which produce deformed flowers should be tossed in the compost. I threw out a nice looking Paph. niveum plant today for that reason. The plant's foliage looked beautiful; but, it bloomed with two flowers and both were the same......horribly deformed. It had a couple siblings with it that bloomed at the same time and they were lovely. I could not charge even $1 for such a disappointing plant.....and donating it would just be a way to look generous to others; while knowing full well that I was passing off garbage as something of value. 'Can't do that....so, I dumped it into the compost pail.
I regularly adjust my prices according to flower quality. The definition of what is "quality" is in the eye of the beholder. Someone interested in competative exhibiting, would not want an average "quality" flower. Other people who are not into exhibiting might even like the lower quality flower better than the "show" plant because the show standards are not what they like. For example: I commented on OrchidIsa's Phrag. Don Wimber and said that I like it because of it's (show), faults....wavy petals. So, a plant that makes "poor quality" flowers is still worthy and desireable to someone. Just make sure that if you charge "show plant" prices, you are selling a show quality plant. I have a price for what I consider "average nice". I have a lower price for anything with less than average quality flowers; but, they are not deformed....they are simply not as good (from a show standard point of view), as the majority of the others. Then of course, the extra special high quality (from a show standard point of view) plants are priced at higher than average. Just always be honest and price accordingly and you can't go wrong. If you ever have a plant with a problem (such as genetic deformities that repeat each time the plant blooms; or, you suspect it of being virused, etc., etc.,), never sell it....and never give it away. Compost it. The rest: sell at a fair price and be fully honest with the customer about the quality of the flower.